Method and apparatus for closing bags



Jan. 17, 1939. R. E. HoczKMAN` METHOD AND APPARATUS .FOR CLOSING BAGSFiled Aug. l2, 1937 '3 Sheets-Sheet l /M/EN TUF; @0555' Hm/WAM 'f7/5ATTU/wfx Jan. 17,1939.

R. E. HOCKMAN 2,144,154

METHOD AND APPARATUS FOR CLOSING BAGS Filed Aug. l2, 1957 3 Sheets-Sheet2 Jan. 17, 1939. R. E. HOCKMAN 2,144,154

METHOD AND APPARATUS FOR CLOSING BAGS Filed Aug. l2, 1937 5 Sheets-Sheet5 /1/'5 A TTFP/VE Y Patented Jan. 17, 1939 PATENT oPPlcE l MErHon ANDAPPARATUS Fon CLOSING.-I

BAGS

`Roger E. Hockman, Middletown, Ohio, assignor to The Raymond BagCompany, Middletown, Ohio, a corporation of Ohio Application August 12,1937, Serial No. 158,774

19 Claims.

This invention relates to a method andapparatus for closing bags and isdesigned primarily for use in the manufacture ofl bags, although it maybe utilized when bags are closed after having 4been lled.

In the manufacture of bags, and more particula'rly in the manufacture ofheavy duty paper bags, it is customary to sever from a continuous tube,or nest of tubes, bag length sections which are then sewed across theends thereof to close the same and form the completed bag. Where bothends of the bag are sewed avalved opening is provided at one end of thebag through which the same may be filled. Usually a tape, such as astrip of paper, is folded about and pasted to j th adjacent ends of theside walls of the bag section and the section is sewed through both lthetape and the side walls. It.is also common .i i practice to apply to oneside of the tapea sealing member, usually of soft cord, and to sewthrough the sealing member, tape and sidewalls. Such a closure issatisfactory for many purposes but it willnot entirely prevent theescape from the bag of finely powdered material and it is not moistureproof, as the sealing member and sewing thread, or stitches, will absorbmoisture from the atmosphere which will travel along the stitches intothe closure and thus bcome in contact with the contents of the bag,which of course is objectionable. In some instances the -contents are of-such a character that the contact `of moisture therewith will produce achemical reaction'which may weaken or destroy the closure.

One object of the present invention is to provide a bag closure of thistype which will prevent the escape of very finely powdered material fromthe bag.

A further object of the invention is to provide such a closure whichwill be moisture proof andA in Fig. 1, partly broken away; Fig. 3 is aplan' View of a portion of the tape which is applied to the ends of thebag sections; Fig. 4 is a side elevation of the end portion of a bagclosed in accordance with my invention; Fig. 5 is a secin the usualmanner.

tional view taken transversely through the closure; Fig. 6 is a sectiontaken lengthwise through a partially completed closure; Fig. 7 is atransverse section of the presser plate; Fig. 8 is a side elevation ofthe presser foot; and Fig. 9 is a detail View, partly in section, of theapparatus for impregnating the sealing member with wax.

In practicing the invention I apply to one side of the bag section,adjacent the end thereof, an elongate sealing member, such as a cord,which has been treated with wax and then stitch this wax treated sealingmember to the bag section As the thread passes through the sealingmember portions of the wax will adhere thereto andbe carried into theneedle openings and if the wax is in a molten or semimolten state at thetime the stitching takes place suiiicient wax may be carried into theneedle openings to seal the same. However, I prefer to subject the sewedclosure, and particularly the wax treated sealing member, to heat whichwill soften the wax and cause the same to flow along the thread orstitches into the needle openings, thus impregnating the thread andcompletely lling the openings with wax.

In carrying out the method in its preferred form the tape I0 which is tobe folded about the end of the bag section II is first provided with aplurality of strips of paste, there being preferably three such stripsI2 and I3, as shown in Figs. 3 and 5. 'I'he two lateral strips of pasteI2 are arranged near the lateral edges of the tape so that when thelatter is folded about the end of the bag section said paste strips willcontact Y the respective side walls of the bag section along linesspaced some distance from the ends thereof. The intermediate strip ofpaste I3 is of a width substantially greater than the lateral strips andis so arranged that when the tape is folded about the bag section thisintermediate strip of paste will engage the edges of and overlap theiendportions of the side walls of the bag, as shown in Fig. 5. The sealingmember, which is shown as a soft cord I4, is treated with wax,preferably by passing the same through a bath of molten wax, such asparaffin, so as to impregnate the sealing member with the wax, and isguided from the bath onto one side of the folded tape III. When the tapeand sealing member have been applied to the end of the bag section thelatter is sewed through the sealing member, the'tape and the side walls.The bath of molten wax is so located with relation to the sewingmechanism that the wax will be in a soft or semi-molten con-v dition atthe time the sewing takes place. After the closure has been stitched itis subjected to the action of heat which will soften the wax and causethe same to penetrate the stitches I5 and needle openings through whichthe stitches extend, as above described.` The sealing member andstitches are thus rendered impervious to moisture and the needleopenings are completely filled with wax. As a result no moisture canenter the bag along the stitches or needle openings and no material canescape from the bag through the needle openings. By pasting the tape tothe end edges of the side walls of the bag section, as shown in Fig. 5,the passage of material between these end edges is entirely prevented.The ends of the tape usually extend a short distance beyond each side ofthe bag, as shown in Fig. 4, and those parts of the pasted strip whichextend beyond the sides of the bag section will each have its sideportions pasted one to the other, thus effectively closing the ends ofthe folded tape.

Any suitable apparatus may be vprovided for carrying out the method asabove described and in the present drawings I have utilized a. bagsewing machine of a well known type to which has been added suchadditional apparatus as was necessary to effect the desired operations.The sewing machine as a Whole is shown in the Sharkey Patent No.1,915,765 of June 27, 1933, and it is not necessary to here illustrateor describe the same in detail. It will be noted that the sewing machinecomprises a supporting structure or table I 6 over which moves a.conveyor, here shown as two endless chains I1 provided with lugs I8toengage the edges of the bag sections I3v and move the sametransversely to their length along the supporting structure to a sewinghead which overhangs the path of the end portions of the bag sectionsand is adapted to perform the necessary sewing operations. The bagsections are held in engagement with the lugs on the conveyor by aseries of longitudinal rods 45 supported at their ends by transversebars 46 which in turn are supported by uprights Orstandards 41 extendingupwardly from the supporting structure. Inasmuch as the sewing head 20forms no part of the linvention it is unnecessary to illustrate ordescribe its construction or opera-tion. This particular sewing machineis a double machine, that is, it is adapted to simultaneously sew bothends of a bag section and is therefore provided on each side with asewing head 20. In adapting this machine to the present purposeadditional parts have been associated with both sewing heads butinasmuch as these parts are duplicates the description of one apparatuswill apply to both.

The tape I0 is fed from a suitable source of supply, such as a roll oftape not here shown, through a paste applying device, which is shown inFigs. 1 and 2, and comprises a roller 2| over which `the tape is drawnand three disks 22 and 23 carried by a common shaft 24, rotating in apaste receptacle 25 and applying the paste to the tape as the latterpasses over the roller 2|. The tape passes from the paste applyingdevice over a guide roller 26 to a folding device 21, of conventionalconstruction, which folds the same about the ends of the bag sections asthe latter `move toward the sewing head.

The means for impregnating the sealing mem- Iber with wax may takevarious forms but preferably this is accomplished by passing the sealing`member through a bath of molten wax and, as here shown, this bath iscontained in a receptacle 28 which is provided with an electric heater29. Any suitable means may be provided for guiding the sealing memberthrough the bath of wax and, in the present instance, where the sealingmember is shown as a cord, the guiding means comprises a tube 30 carriedby the receptacle 28 and having a downwardly curved portion 3l thereofimmersed in the molten wax and provided with a plurality of openings,such as the elongate slots 32, to permit the molten wax to contact withthe cord. One of the slots, the last one which the cord passes, has itsupper end arranged above the level of the liquid in the receptacle andthe diameter of the tube with relation to the thickness of the cord issuch that the end wall 33 of this slot will act on the cord with awiping action to remove therefrom surplus wax and return the same to thereceptacle. The end of the tube on one side of the receptacle 28 isturned downwardly to receive the cord as it is drawn from a suitablesource of supply, here shown as a ball of cord 34 supported on a shelf35a. Ihat portion of the tube on the other side of the receptacle 28extends from the receptacle to a point above the folded tape in advanceof the sewing head so that as the sealing cord leaves the tube I4 it isapplied to the tape, and the discharge end of the tube I4 is so arrangedthat this cord will be located on the tape between the pasted portionsof the latter.

Associated with the sewing head is a plate 35 which exerts pressure onthe tape to cause the pasted portions thereof to adhere firmly to thewalls of the bag section, and which preferably constitutes thepresser-foot of the sewing machine. This plate is provided in its lowerside with a longitudinal groove or guideway 36 to receive and permit thepassage of the sealing cord. That end of the plate 35 in advance of theneedle 3l of the sewing head is turned upwardly, as shown at 38, andprovided with anA opening 33 which merges into the groove 36 and theouter end of which is arranged to receive the sealing cord from the tube30. With the walls of the bagsection, the two sides of the tape and thesealing member thus arranged in superposed relation tohe needle 31 ofthe sewing head operates through an opening 40 in the plate 35 to stitchthese several parts one to the other.

Any suitable means may be employed for applying heat to the bag closurefor the purpose of again softening the wax and this means may be locatedin any suitable relation to the sewing head. 'I'he tape and sealing cordare continuous -a light pressure which will expedite the fiow of meltedwax therefrom along the stitches. When the bag section leaves theheating members 42 the closure has been'completed and the finished bagis discharged from the machine.

The tape I3 and sealing cord I4 are drawn from their sources of supplyrespectively through the tape supplying device land the waxbath byPreferably the memtheir connection with the bag sections which it isunnecessary to provide other means for feeding the same to the bagsections. For simplicity of illustration I have illustrated theinvention as applied to a single ply bag, that is, a bag formed from asingle tube but it will be understood that the invention is equallyapplicable to multi-wall bags, that is, bags formed from a plurality ofnested tubes.

While I have shown and described the preferred method of practicing myinvention and one form for carrying out that method I wish it to beunderstood that I do not wish to be limited to the details thereof asvarious modifications of the method and of the apparatus may occur to aperson skilled in the art.

Having now fully described my invention, what I claim as new and desireto secure by Letters Patent, is:

1. The method of closing the end of a bag which comprises treating amoving sealing men ber with Wax, applying said sealing member to theouter surface of one side wall of a moving bag, stitching said sealingmember to both Walls of said bag, and heating said sealing member tosoften the wax and cause the same to enter the openings formed in saidbag walls by the stitching.

2. The method ofclosing the end of a bag which comprises folding amoving tape about the adjacent ends of the two side walls of a movingbag, treating a moving sealing member with wax, applying said sealingmember to said tape on one side of said moving bag-stitching saidsealing member and said tape to said side Walls, and subjecting saidsealing member to heat to soften said wax and cause the same to flow`along the stitches and through the needle openings in said tape andsaid walls.

3. The method of closing the end of a bag which comprises impregnating asealing member with molten wax, arranging said sealing member on oneside of said bag and sewing the same to both walls of said bag beforesaid yvax has solidified, and thereafter subjecting said sealing memberand the sewed portion of said bag to heat to soften the wax and causethe same to spread throughout the openings formed in the bag walls bythe sewing operation.

4. The method of closing the end of a bag which comprises folding a tapeabout the adjacent `ends of the two side walls of the bag and pastingthe same to said side walls, impregnating a sealing member with moltenwax, applying said sealing member to said tape and sewing said sealingmember and said tape to said side walls before said wax has. solidified.

5. The method of closing the end of a bag which comprises folding a tapeabout the adjacent ends of the two side walls of the bag and past-ingthe same to said side walls, impregnating a sealing member with moltenwax, applying said sealing member to said tape, sewing said sealingmember and said tape to said side walls, and thereafter applying heat tosaid sealing member to soften the wax and cause the same to permeate thestitches and fill the needle openings in said side walls.

6. The method of closingthe end of a bag which comprises impartingcontinuous movement to a bag section transversely to its length, foldinga tape about the open end of the moving bag section, passing a, sealingcord through a bath of molten wax, applying said cord to said tape atone side of the moving bag section, and sewing said cord and said tapeto the side walls of said moving bag section.

'7L The method of closing the end of a bag which comprises impartingcontinuous movement to abag section transversely to its length, foldinga tape about the open end of the moving bag section, passing a sealingcord through a bath of molten wax, applying said cord to said tape atone side of the moving bag section, sewing said cord and said tape tothe side walls of said moving bag section, and thereafter applying heatto the sewed end of said moving bag section.

8. The method of closing the end of a bag which comprises folding a tapeabout the adjacent ends of the side walls of said bag, pasting theintermediate longitudinal portion of said tape to the edges of saidwalls, pasting the lateral portions of said tape to the respective wallsalong lines spaced from the edges thereof, impregnating a sealing memberwith wax, applying said' sealing member to one side of said tape betweenthe pasted portions of the latter, sewing said sealing member and saidtape to said walls, and applying heat to said sealing member to softensaid wax.

9. The method of closing the end of a bag `which comprises folding atape about the adjacent ends of the side Walls of said bag, passing asealing cord through a bath of molten wax, removing surplus wax fromlsaid cord, applying said cord to said tape on one side of said bag, and

sewing said cord and said tape to said side walls.

v10. In a bag sewing machine, means for moving a bag sectiontransversely to its length, means for impregnating a sealing member withwax, means for applying said impregnated sealing member to one side ofsaid moving bag section in spaced relation to the end of the latter, asewing head arranged to act on said bag' section to stitch said sealingmember to the walls of said bag section, and means for applying heat tosaid sealing member.

l1. In a bag sewing machine, means for moving a bag section transverselyto its length, means for impregnating a sealing member with wax, meansfor applying said impregnated sealing member to one side of said movingbag section in spaced relation to the end of the latter, a sewing headarranged to act on said bag section to stitch said sealing member to thewalls of said b-ag section, and a heater arranged beyond said sewinghead adjacent to the path of said sewed end of said bag section.

12. In a bag sewing machine, means for moving a` bag sectiontransversely to its length, means for folding a tape about one end ofsaid moving bag section, a receptacle for molten wax, means for guidinga sealing member through the molten wax in said receptacle and onto saidfolded tape, and a sewing head arranged to stitch said sealing memberand said tape to the walls of said bag section.

13. In a bag sewing machine, means for moving a bag section transverselyto its length, means for folding a tape about one end of said moving bagsection, a receptacle for molten wax, means for guiding a sealing memberthrough the molten wax in said receptacle and onto said folded tape, asewing head arranged to stitch said sealing member and said tape to thewalls of said bag section, and a heater arranged beyond said sewing headand `adjacent to the path of the stitched end of said bag section.

14. In a bag sewing machine, means for moving a bag section transverselyto its length, means for folding a tape about one end of said saidmoving bag section, a receptacle for moltenv wax, means for guiding asealing member through the wax in said receptacle and onto said foldedtape, a plate arranged above the path of the end portion of said bagsection to exert pressure on said tape and having a groove to receivesaid sealing member, and means adjacent to said plate for sewing saidsealing member and said tape to the walls of said bag section.

16. In a bag sewing machine, means for moving a bag section transverselyto its length, means for folding a tape about one end of said moving bagsection, a receptacle for molten wax, means for guiding a sealingmember` through the molten wax in said receptacle and onto said foldedtape and for removing surplus wax from said sealing member, and meansfor sewing said sealing member and said tape to the walls of saidbagsection.

17. In a bag sewing machine, means for moving a bag section transverselyto its length, means for folding a tape about one end of said moving bagsection, a receptacle for molten wax,

a tube extending through said receptacle, havingopenings therein andarranged to guide a sealing member through the molten wax in saidreceptacle, means to guide said sealing member onto said tape, and meansfor sewing said sealing member and said tape to the walls of said bagsection.

18. In a bag sewing machine, means for -moving a. bag sectiontransversely to its length, means for applying paste to a continuoustape, means for folding said tape about the end of said moving bagsection, a receptacle for molten wax, a tube arranged to guide a sealingcord onto said tape and having a portion immersed in the molten wax insaid receptacle and provided with openings, one of said openings havingan end Wall arranged above the level of said wax to remove surplus waxfrom said cord, a plate to exert pressure on said tape, having alongitudinal guideway arranged to receive said cord from said tube andhaving a transverse opening, means including a needle operating throughthe opening in said plate to sew said cord and said tape to the walls ofsaid bag section, and heating elements arranged beyond said sewing meansto receive between them the sewed end of said bag section.

19. The method of closing the end of a bag which comprises saturating asealing member of soft absorbent material with molten wax, arrangingsaid sealing member on one side of said bag and sewing the same theretoby stitching through said sealing member, the Wax therein and both sideWalls of said bag before the wax has solidified. l

ROGER E. HOCKMAN.

